#include <stdio.h>
#include "fun_ext.h"

// gcc fun.c fun_ext.c -o main
int main(void)
{
    float circle_area;
    float radius;

    scanf("%f", &radius);

    circle_area = area(radius);
    printf("circle radius: [%f], area: [%f]", radius, circle_area);

    return 0;
}
